EP1369166A1 - Zeolith membrane of small thickness, its preparation and its use in separation - Google Patents
Zeolith membrane of small thickness, its preparation and its use in separation Download PDFInfo
- Publication number
- EP1369166A1 EP1369166A1 EP03291117A EP03291117A EP1369166A1 EP 1369166 A1 EP1369166 A1 EP 1369166A1 EP 03291117 A EP03291117 A EP 03291117A EP 03291117 A EP03291117 A EP 03291117A EP 1369166 A1 EP1369166 A1 EP 1369166A1
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- EP
- European Patent Office
- Prior art keywords
- separation
- membrane according
- zeolitic
- membrane
- silica
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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- 239000012528 membrane Substances 0.000 title claims abstract description 122
- 238000000926 separation method Methods 0.000 title claims abstract description 48
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 title claims abstract description 42
- 238000002360 preparation method Methods 0.000 title claims description 18
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 57
- 239000010457 zeolite Substances 0.000 claims abstract description 47
- NNPPMTNAJDCUHE-UHFFFAOYSA-N isobutane Chemical compound CC(C)C NNPPMTNAJDCUHE-UHFFFAOYSA-N 0.000 claims abstract description 44
- 229910021536 Zeolite Inorganic materials 0.000 claims abstract description 41
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 26
- 239000001282 iso-butane Substances 0.000 claims abstract description 22
- 239000002131 composite material Substances 0.000 claims abstract description 17
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 18
- 239000007789 gas Substances 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 17
- 238000002425 crystallisation Methods 0.000 claims description 16
- 230000008025 crystallization Effects 0.000 claims description 16
- 230000008569 process Effects 0.000 claims description 14
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 6
- 229930195733 hydrocarbon Natural products 0.000 claims description 6
- 150000002430 hydrocarbons Chemical class 0.000 claims description 6
- 239000001257 hydrogen Substances 0.000 claims description 6
- 229910052739 hydrogen Inorganic materials 0.000 claims description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 6
- -1 of isomers xylenes Chemical class 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- 150000001336 alkenes Chemical class 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 4
- 239000008119 colloidal silica Substances 0.000 claims description 4
- 230000008030 elimination Effects 0.000 claims description 4
- 238000003379 elimination reaction Methods 0.000 claims description 4
- 239000005373 porous glass Substances 0.000 claims description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 2
- 239000000919 ceramic Substances 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 2
- 239000008096 xylene Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 239000000243 solution Substances 0.000 description 18
- 239000013078 crystal Substances 0.000 description 10
- 239000002243 precursor Substances 0.000 description 10
- LPSKDVINWQNWFE-UHFFFAOYSA-M tetrapropylazanium;hydroxide Chemical compound [OH-].CCC[N+](CCC)(CCC)CCC LPSKDVINWQNWFE-UHFFFAOYSA-M 0.000 description 10
- 238000005259 measurement Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 238000012512 characterization method Methods 0.000 description 6
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 5
- 239000000908 ammonium hydroxide Substances 0.000 description 5
- 238000003786 synthesis reaction Methods 0.000 description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- KDKYADYSIPSCCQ-UHFFFAOYSA-N but-1-yne Chemical compound CCC#C KDKYADYSIPSCCQ-UHFFFAOYSA-N 0.000 description 4
- 239000001273 butane Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 239000012153 distilled water Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000010335 hydrothermal treatment Methods 0.000 description 3
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- HSFWRNGVRCDJHI-UHFFFAOYSA-N Acetylene Chemical compound C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- 229910002019 Aerosil® 380 Inorganic materials 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical class CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229940082150 encore Drugs 0.000 description 2
- 239000012510 hollow fiber Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 150000004679 hydroxides Chemical class 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000011147 inorganic material Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000012466 permeate Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- MWWATHDPGQKSAR-UHFFFAOYSA-N propyne Chemical compound CC#C MWWATHDPGQKSAR-UHFFFAOYSA-N 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N Propene Chemical compound CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 150000007514 bases Chemical group 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 150000003983 crown ethers Chemical class 0.000 description 1
- 239000002739 cryptand Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008521 reorganization Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000005049 silicon tetrachloride Substances 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 230000007847 structural defect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 125000000383 tetramethylene group Chemical class [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 150000003738 xylenes Chemical class 0.000 description 1
- 239000012690 zeolite precursor Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/02—Inorganic material
- B01D71/028—Molecular sieves
- B01D71/0281—Zeolites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0039—Inorganic membrane manufacture
- B01D67/0051—Inorganic membrane manufacture by controlled crystallisation, e,.g. hydrothermal growth
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
- B01D53/228—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion characterised by specific membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/02—Inorganic material
- B01D71/028—Molecular sieves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
-
- B01J35/59—
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/144—Purification; Separation; Use of additives using membranes, e.g. selective permeation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/12—Specific ratios of components used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/20—Specific permeability or cut-off range
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
- B01J2229/60—Synthesis on support
- B01J2229/64—Synthesis on support in or on refractory materials
Definitions
- the present invention relates to the field of supported zeolitic membranes used in separation.
- zeolitic membrane More particularly, it relates to a supported zeolitic membrane, a process for its preparation and its use in separation.
- inorganic materials can in general be used at relatively high temperatures, for example higher than organic polymer membranes which generally operate at a temperature below 100 ° C. It is therefore essential, for a industrial and commercial application, to have a membrane which can remain stable during of operations and implementation at high temperatures or even high pressures.
- the way hydrothermal involving porous supports has the advantage of stabilizing the crystals of zeolites in the porosity of a porous matrix (alumina, stainless steel for example) and on the surface thereof.
- the increase in thickness can considerably limit the transfer of material through the membrane during the separation operation and thus reduce the technical interest and economical operation of the membrane separation operation, due to a reduction in productivity of said separation step.
- a membrane with a thick separating layer will require use large areas of said membrane material to treat a charge rate of mixture to be separated, which translates into high investments.
- this mode of synthesis in several stages requires a large quantity of the precursors of the zeolitic phase, which notably increases the cost of the raw materials and precursors used. It also presents the disadvantage of lengthening the duration of obtaining the membrane material and increasing the cost separation operation.
- One of the difficulties associated with the preparation of zeolite-based membranes lies in particular in the control of the crystallization of the zeolite in order to obtain zeolite crystals well bound to the support, located mainly in the porosity of the support, thus forming a composite layer zeolite / continuous support (obtained by obstructing the empty spaces of the support with phase crystals zeolitic) and fine so as to limit the resistance of transfer through the membrane material.
- the majority localization, preferably integral, of the zeolitic phase in the porosity of the support gives very good thermal and mechanical resistance to the membrane material. However, it is not not excluded that a minority part of the zeolitic phase is localized on the external surface of the support.
- said zeolitic phase which is active in separation, that is to say selective with respect to the compounds to be separated, is fine and also has a very high crystallinity.
- the supported zeolitic membrane according to the invention consists of a zeolite / support composite layer and is characterized in that it exhibits, in the n-butane / isobutane separation, a permeance of n-butane of at least 6. 10 -7 mol / m 2 .s.Pa and a selectivity of at least 250 at a temperature of 180 ° C.
- the permeance of a gas is the molar flow rate (mol / s) of this gas reduced to the unit of surface area (m 2 ) membrane and reduced to the partial pressure difference of this gas between the upstream (where the charge circulates) and the downstream (where the permeate is recovered).
- the permeance of a gas is therefore the molar flow rate of this gas passing through the membrane per unit area and pressure.
- the selectivity ⁇ (called permselectivity) is, in the case of permeation measurements of pure bodies, the ratio of the permeances of these pure bodies. In the context of the present invention, the selectivity is therefore the ratio of the permeances of n-butane and isobutane.
- the supported zeolitic membrane according to the invention has, in the n-butane / isobutane separation, a permeance of n-butane of at least 8.10 -7 mol / m 2 .s.Pa and very preferably of at least 10.10 -7 mol / m 2 .s.Pa at a temperature of 180 ° C.
- the high permeance of n-butane of the membranes according to the invention testify to the small thickness of the zeolitic phase as well as that of the zeolite / support composite layer which has a thickness of less than 2 ⁇ m and preferably less than 1 ⁇ m and very preferred less than 0.5 ⁇ m.
- the permeance is measured as follows: the membrane is inserted into a permeator (permeation measurement module) using carbon seals, which maintain the tightness of this measurement module.
- the assembly (module / membrane) is placed in a gas permeation unit and the material is first treated at 350 ° C under a flow of inert gas such as helium which eliminates any trace of adsorbable gas on the external surface and in the internal porosity of the membrane material.
- the membrane is subjected to a pressure difference, the pressure on the upstream side where the charge circulates (pure butane nC 4 H 10 or pure isobutane iC 4 H 10 ) is kept constant at 1.5 bar (0.15 MPa) absolute and the pressure on the downstream side, where the permeate is recovered after selective extraction of part of the molecules present in the charge, is atmospheric pressure.
- This pressure difference constitutes the driving force of the transfer through the membrane.
- the gas flow through the membrane is measured using a volume flow meter.
- the detection threshold is less than 0.002 mL / min or about 10 -6 mol / m 2 .s of n-butane or isobutane.
- the gas flow rates passing through the membrane are measured with pure n-butane and isobutane bodies.
- the temperature is maintained at 180 ° C.
- this characterization method is considered to be a very strict and very selective criterion for characterizing microporous inorganic membranes and in particular zeolitic membranes. . It therefore makes it possible to highlight the presence of any discontinuity, defects, cracks in the composite zeolite / support layer. Conversely, the absence of significant defects in the membrane reveals a very high potential for separation.
- this characterization method using n-butane and isobutane is very severe compared to other characterization tests used in the prior art, for example tests using the couples N 2 / SF 6 , H 2 / nC 4 or H 2 / iC 4 .
- the supported zeolitic membrane according to the invention has a selectivity of at least minus 1000.
- the zeolitic membrane supported according to the invention consists of a composite layer zeolite / continuous and fine support, the zeolitic phase of which is also fine, which results in very high separating performance, in particular by a selectivity or separating power of the very high membrane, that is to say at least 250, preferably at least 1000, or even infinite.
- said zeolite / support composite layer is active in separation, that is to say selective with respect to compounds to be separated.
- the membranes according to the invention are composite materials, of which the selective or separating layer is formed of zeolite crystals immobilized and stabilized in the porosity of an inorganic support.
- the zeolitic phase is mainly, preferably fully located in the porosity of the support, which gives very good resistance thermal and mechanical with membrane material.
- This zeolitic phase has a crystallinity very high, preferably at least 85% and very preferably at least 90%.
- Membranes zeolites according to the invention also exhibit very good structural integrity, that is to say an absence of defects in the structure of the zeolite / support composite layer and an absence interparticle spaces, that is, voids between the crystals of the zeolite, which is difficult to obtain by prior methods in one step.
- the finesse of the zeolitic layer does not prevent advantageously using the membrane according to the invention at high temperatures, especially above 100 ° C (such as 180 ° C for example).
- the zeolitic phase contained in said composite layer is preferably of MFI structural type (silicalite-1 or ZSM-5) with channel dimensions of 0.51 * 0.55 and 0.53 * 0.56 nm 2 .
- the support included in the zeolite / membrane support layer according to the invention is made of porous inorganic material.
- a ceramic support based on alumina and / or Zirconia and / or titanium oxide is a suitable support.
- Other materials, the nature of which follows, may also be suitable: carbon, silica, zeolites, clays, porous glass, porous metal.
- the use of an alumina support of alpha or gamma allotropic variety is preferred.
- This support may be, for example, in planar or tubular form or in the form of hollow fibers or many more multi-channel monoliths. Other geometries may be suitable, but the geometries of support compatible with industrial use of these membranes are advantageously employed.
- tubular supports and supports in the form of hollow fibers allow to operate compact modules and units (membrane surface / volume ratio of high equipment) to handle large load flows.
- the present invention also relates to a process for the controlled production of membranes zeolites according to the invention.
- the source of silica used in step (a) of the process is preferably a colloidal silica or a precipitated silica. It can also be silicate ions such as sodium silicate, alkoxides of silicon or silicon tetrachloride.
- step (a) of the process according to the invention can also be introduced in a minority quantity during step (a) of the process according to the invention.
- elements can also be introduced in a minority quantity during step (a) of the process according to the invention.
- aluminum, boron, gallium, titanium, germanium and phosphorus as well as the mixture of these elements can be added during step (a).
- the polar organic compound added to the gel or to the solution comprising at least said source of silica and water is preferably a basic compound.
- these are hydroxides organic, such as tetrapropylammonium hydroxide, organic structuring agents containing ion pairs (ammonium or phosphonium ions and the corresponding anions) or molecules neutral (amines, alcohols or ethers such as crown ethers and cryptands).
- the molar ratio of the polar organic silica compound is between 0.3: 1 and 0.6: 1 and preferably between 0.35: 1 and 0.50: 1.
- Hydroxide or fluoride ions can also be used for the dissolution of precursors and are introduced into the preparation medium, for example in the form of hydroxide sodium, organic hydroxides and hydrofluoric acid.
- the dilution of the silica source in the solution or gel used in step (a) and the duration of crystallization of the zeolite in step (c) are essential parameters to master in order to reach the desired properties of the zeolitic phase deposited in the porosity of the support.
- a particular embodiment of the process according to the invention consists in using a precipitated silica as a source of silica in step (a), in a molar ratio of water to silica of between 45: 1 and 65: 1 and to apply in step (c) a crystallization time of less than or equal to 80 hours.
- Another particular embodiment of the method according to the invention consists in using a silica colloidal as source of silica in step (a), in a molar ratio of water to silica included between 18: 1 and 35: 1 and to apply in step (c) a crystallization time less than or equal to 45 hours.
- the crystallization of the zeolite in step (c) of the process according to the invention is carried out in a single step, that is to say that the zeolite is crystallized by a single hydrothermal treatment.
- the removal of residual agents, mainly of the polar organic compound, in accordance with step (d) of the process according to the invention, is carried out by heat treatment carried out between 350 and 550 ° C, preferably between 400 ° C and 500 °. C, in an oven under air atmosphere or under N 2 / O 2 atmosphere in variable proportions.
- the microporosity of the zeolitic membranes can then be used for a separation operation.
- the calcination at high temperature that is to say carried out between 350 and 550 ° C., preferably between 400 ° C. and 500 ° C., of the membrane in order to remove the residual agents has no influence on the performances. separators of the membrane, which remain very satisfactory.
- zeolitic membranes according to the invention therefore appear to be particularly suitable for separations at high as well as at low temperatures, in industrial processes which require the treatment of sometimes large amounts of filler, while limiting the investment required (membranes of high permeability).
- the quality and the molecular sieving properties of the zeolitic phase are used to separate molecules whose dimensions are strictly less on the one hand and on the other hand strictly greater than those of the pores of the zeolite (separation by size differentiation).
- the zeolitic membranes according to the invention can be used for the separation of molecules, in particular containing carbon and hydrogen atoms, the dimensions of which are on the one hand less than approximately 0.45 nm and on the other hand greater than 0.55 nm.
- the interactions between the molecules to be separated and the zeolitic phase of the membrane can also be used to effect the separation of said molecules (separation by adsorption).
- Example 1 Preparation of a zeolitic membrane (according to the invention)
- a zeolite precursor solution is prepared from a source of silica (Aerosil 380® with a specific surface area equal to 380 m 2 / g sold by the company Degussa), mixed at room temperature with distilled water and a solution molar aqueous of the polar organic agent of tetrapropylated ammonium hydroxide TPAOH (Fluka).
- TPAOH tetrapropylated ammonium hydroxide
- the resulting solution admits for molar composition: 1 SiO 2 : 0.4 TPAOH: 63.7 H 2 O.
- This solution is left to mature with vigorous stirring for 72 hours, which allows a partial depolymerization and a reorganization of the silica into species more reactive silicates than the original source.
- Partial gelation of the precursors may occur, the solution being more or less clear.
- a porous support of alpha alumina (sold by the company Exekia), previously washed with distilled water and then dried at 60 ° C., is then immersed in the solution prepared above. All the precursors and the porous support are placed in a sealed autoclave, inserted in an oven maintained at 175 ° C for 60 hours. After returning to room temperature, the membrane is collected and washed with distilled water and then dried at 60 ° C. Removal of residual agents, mainly tetrapropylated ammonium hydroxide TPAOH, is carried out by heat treatment at 480 ° C in an oven under air atmosphere.
- TPAOH tetrapropylated ammonium hydroxide
- the microporosity of the zeolitic membranes can then be used for a separation operation.
- Phase analysis by X-ray diffraction on this membrane obtained after 60 hours of autoclaving confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
- Example 2 Preparation of a zeolitic membrane (according to the invention)
- the preparation protocol is similar to that described in Example 1 but the preparation is carried out in the presence of a source of colloidal silica, Bindzil 40 / 130® (sold by the company Akzo Nobel).
- Bindzil 40 / 130® sold by the company Akzo Nobel.
- TPAOH 18.3 H 2 O.
- the crystallization time is 30 hours .
- Removal of residual agents, mainly tetrapropylated ammonium hydroxide TPAOH is carried out by heat treatment at 480 ° C in an oven under air atmosphere.
- the microporosity of the zeolitic membranes can then be used for a separation operation.
- Phase analysis by X-ray diffraction on this membrane obtained after 30 hours of autoclaving confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
- Example 3 Preparation of zeolitic membranes (not in accordance with the invention)
- Example 1 The operating protocol described in Example 1 is repeated by modifying only the quantity of water introduced into the precursor solution of the MFI zeolite and the crystallization time.
- the source of silica is Aerosil 380®.
- the crystallization time is 72 hours and the elimination of the hydroxide TPAOH tetrapropylated ammonium hydroxide is carried out at 480 ° C.
- Example 2 The operating protocol described in Example 2 is repeated by modifying only the duration of crystallization.
- the source of silica is Bindzil 40 / 130®.
- the crystallization time is 72 hours and the elimination of the tetrapropylated ammonium hydroxide TPAOH is carried out at 480 ° C.
- Example 4 Separating performances of zeolitic membrane materials (in accordance with the invention)
- membranes (A, B, C, D, E) are prepared according to the method of synthesis described in Example 1.
- the membrane E is obtained according to the method of synthesis described in example 1 but with a duration of 72 hour crystallization.
- membranes A, B, C, D, E and F according to the invention are demonstrated by gas separation measurement (gas permeation), carried out using n-butane and isobutane according to the protocol described above in the description.
- the zeolitic membranes according to the invention exhibit, at the end of the characterization measurements, very high permeances, most of them greater than 10.10 -7 mol / m 2 .s.Pa of n-butane at the temperature of 180 ° C., which reflects a very small thickness of the zeolitic membranes A, B, C, D, E and F. Under the same conditions, these materials are impermeable to isobutane (A, D, E, F) or their permeances are very low (B and C), in all cases less than 0.065.10 -7 mol / m 2 .s.Pa of isobutane.
- n-butane / isobutane or nC 4 H 10 / iC 4 H 10 reaches particularly high values, in all cases greater than 250 and the separation is particularly effective, which testifies to the continuity of the composite layer.
- zeolitic membranes of the MFI structural type exhibit good textural integrity, that is to say an absence of structural defects of the mesopore and macropore type, when the selectivity n-butane / isobutane is greater than 10 (Vroon et al., J. Membr. Sci. 113 (1996) 293).
- Example 5 separating performances of zeolitic membrane materials (non-conforming to the invention)
- the membranes G and H present in the n-C4 / i-C4 separation permeances of n-butane well lower than those of the membranes according to the invention.
- the membranes according to the invention have in effect a permeance of n-butane about 2 to 11 times higher than that of non-membranes in accordance with the invention, while retaining high or even infinite selectivities.
- the membranes according to the invention contain a zeolite / support composite layer which can be up to at least 11 times thinner than that of non-conforming membranes.
Abstract
Description
La présente invention se rapporte au domaine des membranes zéolithiques supportées utilisées en séparation.The present invention relates to the field of supported zeolitic membranes used in separation.
Elle a plus particulièrement pour objet une membrane zéolithique supportée, un procédé pour sa préparation et son utilisation en séparation.More particularly, it relates to a supported zeolitic membrane, a process for its preparation and its use in separation.
Divers procédés d'élaboration de membranes zéolithiques ont déjà été décrits. Il apparaít à ce jour difficile d'obtenir de manière contrôlée et reproductible des membranes zéolithiques dont la couche contenant la zéolithe est continue et fine. La finesse et la continuité d'une telle couche sont des paramètres essentiels pour obtenir un matériau membranaire présentant des propriétés intéressantes qui puissent être mises à profit dans des procédés de séparation industriels. Notamment, il est particulièrement difficile de maítriser la préparation des membranes zéolithiques: les procédés d'obtention font intervenir plusieurs étapes et il est souvent nécessaire de reproduire l'étape de cristallisation à plusieurs reprises pour obtenir, à la suite d'étapes consommatrices en temps, en coûts opératoires, en produits chimiques et en énergie, une couche continue qui puisse être mise en oeuvre en séparation. Par ailleurs, la stabilité thermique et mécanique de ces membranes inorganiques est cruciale. En effet, les matériaux inorganiques, peuvent en général, être mis en oeuvre à des températures relativement élevées, par exemple plus élevées que les membranes polymères organiques qui opèrent généralement à une température inférieure à 100°C. Il est alors essentiel, pour une application industrielle et commerciale, de disposer d'une membrane qui puisse demeurer stable lors d'opérations et de mises en oeuvre à des températures élevées voire de pressions élevées. La voie hydrothermale mettant en jeu des supports poreux présente l'avantage de stabiliser les cristaux de zéolithes dans la porosité d'une matrice poreuse (alumine, inox par exemple) et à la surface de celle-ci.Various processes for developing zeolitic membranes have already been described. It appears to date difficult to obtain in a controlled and reproducible manner zeolitic membranes whose layer containing the zeolite is continuous and fine. The thinness and continuity of such a layer are essential parameters for obtaining a membrane material having interesting properties which can be used in industrial separation processes. In particular, it is particularly difficult to control the preparation of zeolitic membranes: the processes of obtaining involve several stages and it is often necessary to reproduce the stage of crystallization several times to obtain, following time consuming steps, in costs operating, chemical and energy, a continuous layer that can be implemented in separation. Furthermore, the thermal and mechanical stability of these inorganic membranes is crucial. In fact, inorganic materials can in general be used at relatively high temperatures, for example higher than organic polymer membranes which generally operate at a temperature below 100 ° C. It is therefore essential, for a industrial and commercial application, to have a membrane which can remain stable during of operations and implementation at high temperatures or even high pressures. The way hydrothermal involving porous supports has the advantage of stabilizing the crystals of zeolites in the porosity of a porous matrix (alumina, stainless steel for example) and on the surface thereof.
Dans la demande de brevet EP-A-0 778 075, il est décrit un procédé d'élaboration de membranes de zéolithe supportée par du verre poreux. Le brevet US-A-5,429,743 et la demande de brevet internationale WO-A-95/29751 décrivent des protocoles d'obtention de membranes composites supportées par une matrice macroporeuse inorganique. On pourra également se référer aux documents US-A-4,099,692, WO-A-93/19840, US-A-5,567,664 et WO-A-96/01683. Dans la demande de brevet internationale WO-A-00/33948, il est décrit un procédé d'obtention de membranes composites de zéolithe supportée sur des solides tubulaires éventuellement multi-canaux. L'ensemble de ces matériaux membranaires composites à base de zéolithe est formé d'une phase zéolithique déposée sur un support. Une série de brevets récents (US 5,871,650, US 5,968,366, US 6,090,289, US 6,074,457, WO-A-00/53297, WO-A-00/53298) décrit la préparation de membranes dont la phase zéolithique MFI se trouve à la surface externe d'un support poreux. La cristallisation de la zéolithe s'effectue généralement par des traitements hydrothermaux multiples d'un mélange contenant les précurseurs de la phase zéolithique, ce qui augmente l'épaisseur effective de la couche séparatrice. Lorsque l'étape de cristallisation de la zéolithe est reproduite à plusieurs reprises, la synthèse est reproduite après retour éventuel du matériau à température ambiante, lavage et séchage dudit matériau. In patent application EP-A-0 778 075, there is described a process for preparing membranes of zeolite supported by porous glass. US-A-5,429,743 and the patent application WO-A-95/29751 describe protocols for obtaining composite membranes supported by an inorganic macroporous matrix. We can also refer to the documents US-A-4,099,692, WO-A-93/19840, US-A-5,567,664 and WO-A-96/01683. In the patent application WO-A-00/33948, there is described a process for obtaining composite membranes of zeolite supported on tubular solids possibly multi-channel. All of these composite membrane materials based on zeolite is formed of a zeolitic phase deposited on a support. A series of recent patents (US 5,871,650, US 5,968,366, US 6,090,289, US 6,074,457, WO-A-00/53297, WO-A-00/53298) describes the preparation of membranes including the MFI zeolitic phase is found on the outer surface of a porous support. The crystallization of the zeolite takes place generally by multiple hydrothermal treatments of a mixture containing the precursors of the zeolitic phase, which increases the effective thickness of the separating layer. When the stage of zeolite crystallization is reproduced several times, the synthesis is reproduced after return any material at room temperature, washing and drying said material.
La répétition et la succession d'opérations identiques pour la préparation de membranes zéolithiques permettent le dépôt de couches successives et/ou la formation de cristaux de zéolithes qui comblent les espaces interparticulaires, ce qui permet l'obtention d'une couche continue pour la séparation. Ce mode de synthèse en plusieurs étapes, s'il conduit à l'obtention d'une couche continue, conduit également à l'obtention de couches épaisses de zéolithes, qui risquent de se fissurer lors de la calcination de la membrane (Vroon, Z.A.E.P., Keizer, K., Burggraaf, A.J., Verweij, H., J. Membr. Sci. 144 (1998) 65-76), de la mise en régime de l'unité de séparation par membrane ou de la mise en oeuvre à haute température. Par ailleurs, l'augmentation d'épaisseur peut considérablement limiter le transfert de matière à travers la membrane lors de l'opération de séparation et diminuer ainsi l'intérêt technique et économique de l'opération de séparation par membrane, dû à une réduction de productivité de ladite étape de séparation. De plus, une membrane dont la couche séparatrice est épaisse nécessitera de mettre en oeuvre des surfaces importantes dudit matériau membranaire pour traiter un débit de charge de mélange à séparer, ce qui se traduit par des investissements élevés. En outre, ce mode de synthèse en plusieurs étapes nécessite une quantité importante des précurseurs de la phase zéolithique, ce qui augmente notamment le coût des matières premières et précurseurs utilisés. Il présente également l'inconvénient d'allonger la durée d'obtention du matériau membranaire et d'augmenter le coût opératoire de la séparation.The repetition and the succession of identical operations for the preparation of zeolitic membranes allow the deposition of successive layers and / or the formation of zeolite crystals which fill the interparticle spaces, which makes it possible to obtain a continuous layer for separation. This mode of synthesis in several stages, if it leads to the production of a continuous layer, leads also to obtain thick layers of zeolites, which may crack during the calcination of the membrane (Vroon, Z.A.E.P., Keizer, K., Burggraaf, A.J., Verweij, H., J. Membr. Sci. 144 (1998) 65-76), the operation of the membrane separation unit or the implementation at high temperature. In addition, the increase in thickness can considerably limit the transfer of material through the membrane during the separation operation and thus reduce the technical interest and economical operation of the membrane separation operation, due to a reduction in productivity of said separation step. In addition, a membrane with a thick separating layer will require use large areas of said membrane material to treat a charge rate of mixture to be separated, which translates into high investments. In addition, this mode of synthesis in several stages requires a large quantity of the precursors of the zeolitic phase, which notably increases the cost of the raw materials and precursors used. It also presents the disadvantage of lengthening the duration of obtaining the membrane material and increasing the cost separation operation.
Une des difficultés liées à la préparation de membranes à base de zéolithe réside notamment dans le contrôle de la cristallisation de la zéolithe afin d'obtenir des cristaux de zéolithe bien liés au support, localisés principalement dans la porosité du support, formant ainsi une couche composite zéolithe/support continue (obtenue en obstruant les espaces vides du support par des cristaux de phase zéolithique) et fine de manière à limiter la résistance de transfert à travers le matériau membranaire. La localisation majoritaire, de préférence intégrale, de la phase zéolithique dans la porosité du support confère une très bonne résistance thermique et mécanique au matériau membranaire. Toutefois, il n'est pas exclu qu'une partie minoritaire de la phase zéolithique soit localisée à la surface externe du support.One of the difficulties associated with the preparation of zeolite-based membranes lies in particular in the control of the crystallization of the zeolite in order to obtain zeolite crystals well bound to the support, located mainly in the porosity of the support, thus forming a composite layer zeolite / continuous support (obtained by obstructing the empty spaces of the support with phase crystals zeolitic) and fine so as to limit the resistance of transfer through the membrane material. The majority localization, preferably integral, of the zeolitic phase in the porosity of the support gives very good thermal and mechanical resistance to the membrane material. However, it is not not excluded that a minority part of the zeolitic phase is localized on the external surface of the support.
C'est un des objets essentiels de la présente invention que de fournir une membrane zéolithique supportée dans laquelle la phase zéolithique, cristallisée par un unique traitement hydrothermal, présente les caractéristiques énoncées ci-dessus. En particulier, ladite phase zéolithique, qui est active en séparation, c'est-à-dire sélective vis-à-vis des composés à séparer, est fine et présente en outre une cristallinité très élevée.It is one of the essential objects of the present invention to provide a zeolitic membrane supported in which the zeolitic phase, crystallized by a single hydrothermal treatment, has the characteristics set out above. In particular, said zeolitic phase, which is active in separation, that is to say selective with respect to the compounds to be separated, is fine and also has a very high crystallinity.
La membrane zéolithique supportée selon l'invention est constituée d'une couche composite zéolithe/support et se caractérise en ce qu'elle présente, dans la séparation n-butane/isobutane, une perméance de n-butane d'au moins 6. 10-7 mol/m2.s.Pa et une sélectivité d'au moins 250 à la température de 180°C.The supported zeolitic membrane according to the invention consists of a zeolite / support composite layer and is characterized in that it exhibits, in the n-butane / isobutane separation, a permeance of n-butane of at least 6. 10 -7 mol / m 2 .s.Pa and a selectivity of at least 250 at a temperature of 180 ° C.
On rappelle, que, par définition, la perméance d'un gaz, exprimée en mol/m2.s.Pa, est le débit molaire (mol/s) de ce gaz ramené à l'unité de surface (m2) membranaire et ramené à la différence de pression partielle de ce gaz entre l'amont (où circule la charge) et l'aval (où l'on récupère le perméat). La perméance d'un gaz est donc le débit molaire de ce gaz traversant la membrane par unité de surface et de pression. La sélectivité α (appelée permsélectivité) est, dans le cas de mesures de perméation de corps purs, le rapport des perméances de ces corps purs. Dans le cadre de la présente invention, la sélectivité est donc le rapport des perméances du n-butane et de l'isobutane.It is recalled that, by definition, the permeance of a gas, expressed in mol / m 2 .s.Pa, is the molar flow rate (mol / s) of this gas reduced to the unit of surface area (m 2 ) membrane and reduced to the partial pressure difference of this gas between the upstream (where the charge circulates) and the downstream (where the permeate is recovered). The permeance of a gas is therefore the molar flow rate of this gas passing through the membrane per unit area and pressure. The selectivity α (called permselectivity) is, in the case of permeation measurements of pure bodies, the ratio of the permeances of these pure bodies. In the context of the present invention, the selectivity is therefore the ratio of the permeances of n-butane and isobutane.
De préférence, la membrane zéolithique supportée selon l'invention présente, dans la séparation n-butane/isobutane, une perméance de n-butane d'au moins 8.10-7 mol/m2.s.Pa et de manière très préférée d'au moins 10.10-7 mol/m2.s.Pa à la température de 180°C. La perméance élevée de n-butane des membranes selon l'invention témoignent la faible épaisseur de la phase zéolithique ainsi que celle de la couche composite zéolithe/support laquelle présente une épaisseur inférieure à 2 µm et de préférence inférieure à 1 µm et de manière très préférée inférieure à 0,5 µm.Preferably, the supported zeolitic membrane according to the invention has, in the n-butane / isobutane separation, a permeance of n-butane of at least 8.10 -7 mol / m 2 .s.Pa and very preferably of at least 10.10 -7 mol / m 2 .s.Pa at a temperature of 180 ° C. The high permeance of n-butane of the membranes according to the invention testify to the small thickness of the zeolitic phase as well as that of the zeolite / support composite layer which has a thickness of less than 2 μm and preferably less than 1 μm and very preferred less than 0.5 µm.
La perméance est mesurée comme suit : la membrane est insérée dans un perméateur (module de mesure de perméation) grâce à des joints de carbone, qui maintiennent l'étanchéité de ce module de mesure. L'ensemble (module/membrane) est placé dans une unité de perméation gazeuse et le matériau est au préalable traité à 350 °C sous un débit de gaz inerte comme l'hélium ce qui permet d'éliminer toute trace de gaz adsorbable sur la surface externe et dans la porosité interne du matériau membranaire. Durant les mesures de perméation de gaz, la membrane est soumise à une différence de pression, la pression du côté amont où circule la charge (du butane linéaire n-C4H10 pur ou de l'isobutane pur i-C4H10) est maintenue constante à 1,5 bar (0,15 MPa) absolus et la pression du côté aval, où l'on récupère le perméat après extraction sélective d'une partie des molécules présentes dans la charge, est la pression atmosphérique. Cette différence de pression constitue la force motrice du transfert à travers la membrane. Le débit de gaz traversant la membrane est mesuré au moyen d'un débitmètre volumique. Le seuil de détection est inférieur à 0,002 mL/mn soit environ 10-6 mol/m2.s de n-butane ou isobutane. La mesure des débits de gaz traversant la membrane est effectuée avec les corps purs n-butane et isobutane. Durant les mesures de perméation de gaz, la température est maintenue à 180°C.The permeance is measured as follows: the membrane is inserted into a permeator (permeation measurement module) using carbon seals, which maintain the tightness of this measurement module. The assembly (module / membrane) is placed in a gas permeation unit and the material is first treated at 350 ° C under a flow of inert gas such as helium which eliminates any trace of adsorbable gas on the external surface and in the internal porosity of the membrane material. During gas permeation measurements, the membrane is subjected to a pressure difference, the pressure on the upstream side where the charge circulates (pure butane nC 4 H 10 or pure isobutane iC 4 H 10 ) is kept constant at 1.5 bar (0.15 MPa) absolute and the pressure on the downstream side, where the permeate is recovered after selective extraction of part of the molecules present in the charge, is atmospheric pressure. This pressure difference constitutes the driving force of the transfer through the membrane. The gas flow through the membrane is measured using a volume flow meter. The detection threshold is less than 0.002 mL / min or about 10 -6 mol / m 2 .s of n-butane or isobutane. The gas flow rates passing through the membrane are measured with pure n-butane and isobutane bodies. During gas permeation measurements, the temperature is maintained at 180 ° C.
Il est à noter qu'avec le choix de ces molécules sondes que sont le n-butane et l'isobutane, cette méthode de caractérisation est considérée comme un critère très sévère et très sélectif pour caractériser des membranes inorganiques microporeuses et en particulier des membranes zéolithiques. Elle permet dès lors de mettre en évidence la présence de toute discontinuité, de défauts, de fissures dans la couche composite zéolithe/support. A l'inverse, l'absence de défauts notables dans la membrane révèle un potentiel très élevé en séparation. En particulier, cette méthode de caractérisation utilisant le n-butane et l'isobutane est très sévère par rapport à d'autres tests de caractérisation employés dans l'art antérieur, par exemple les tests utilisant les couples N2/SF6, H2/n-C4 ou H2/i-C4.It should be noted that with the choice of these probe molecules that are n-butane and isobutane, this characterization method is considered to be a very strict and very selective criterion for characterizing microporous inorganic membranes and in particular zeolitic membranes. . It therefore makes it possible to highlight the presence of any discontinuity, defects, cracks in the composite zeolite / support layer. Conversely, the absence of significant defects in the membrane reveals a very high potential for separation. In particular, this characterization method using n-butane and isobutane is very severe compared to other characterization tests used in the prior art, for example tests using the couples N 2 / SF 6 , H 2 / nC 4 or H 2 / iC 4 .
De préférence, la membrane zéolithique supportée selon l'invention présente une sélectivité d'au moins 1000. Preferably, the supported zeolitic membrane according to the invention has a selectivity of at least minus 1000.
La membrane zéolithique supportée selon l'invention est constituée d'une couche composite zéolithe/support continue et fine dont la phase zéolithique est également fine, ce qui se traduit par des performances séparatrices très élevées, en particulier par une sélectivité ou pouvoir séparateur de la membrane très élevée, c'est-à-dire d'au moins 250, de préférence d'au moins 1000, voire infinie. Ladite couche composite zéolithe/support est active en séparation, c'est-à-dire sélective vis-à-vis des composés à séparer. Par ailleurs les membranes selon l'invention sont des matériaux composites, dont la couche sélective ou séparatrice est formée de cristaux de zéolithe immobilisés et stabilisés dans la porosité d'un support inorganique. La phase zéolithique est majoritairement, de préférence intégralement, localisée dans la porosité du support, ce qui confère une très bonne résistance thermique et mécanique au matériau membranaire. Cette phase zéolithique présente une cristallinité très élevée, de préférence d'au moins 85% et de manière très préférée d'au moins 90%. Les membranes zéolithiques selon l'invention présentent également une très bonne intégrité structurale, c'est-à-dire une absence de défauts dans la structure de la couche composite zéolithe/support et une absence d'espaces interparticulaires, c'est-à-dire de vides présents entre les cristaux de la zéolithe, ce qu'il est difficile d'obtenir par les procédés antérieurs en une seule étape. La finesse de la couche zéolithique n'empêche pas d'utiliser avantageusement la membrane selon l'invention à des températures élevées, notamment supérieures à 100°C (comme par exemple 180°C).The zeolitic membrane supported according to the invention consists of a composite layer zeolite / continuous and fine support, the zeolitic phase of which is also fine, which results in very high separating performance, in particular by a selectivity or separating power of the very high membrane, that is to say at least 250, preferably at least 1000, or even infinite. said zeolite / support composite layer is active in separation, that is to say selective with respect to compounds to be separated. Furthermore, the membranes according to the invention are composite materials, of which the selective or separating layer is formed of zeolite crystals immobilized and stabilized in the porosity of an inorganic support. The zeolitic phase is mainly, preferably fully located in the porosity of the support, which gives very good resistance thermal and mechanical with membrane material. This zeolitic phase has a crystallinity very high, preferably at least 85% and very preferably at least 90%. Membranes zeolites according to the invention also exhibit very good structural integrity, that is to say an absence of defects in the structure of the zeolite / support composite layer and an absence interparticle spaces, that is, voids between the crystals of the zeolite, which is difficult to obtain by prior methods in one step. The finesse of the zeolitic layer does not prevent advantageously using the membrane according to the invention at high temperatures, especially above 100 ° C (such as 180 ° C for example).
La phase zéolithique contenue dans ladite couche composite est de préférence de type structural MFI (silicalite-1 ou ZSM-5) avec des dimensions de canaux de 0.51*0.55 et 0.53*0.56 nm2.The zeolitic phase contained in said composite layer is preferably of MFI structural type (silicalite-1 or ZSM-5) with channel dimensions of 0.51 * 0.55 and 0.53 * 0.56 nm 2 .
Le support compris dans la couche composite zéolithe/support de la membrane selon l'invention est constitué d'un matériau inorganique poreux. Un support en céramique à base d'alumine et/ou de zircone et/ou d'oxyde de titane est un support approprié. D'autres matériaux, dont la nature suit, peuvent également convenir: carbone, silice, zéolithes, argiles, verré poreux, métal poreux. L'utilisation d'un support en alumine de variété allotropique alpha ou gamma est préférée. Ce support peut se présenter, par exemple, sous forme plane ou tubulaire ou sous la forme de fibres creuses ou bien encore de monolithes multi-canaux. D'autres géométries peuvent convenir, mais les géométries de support compatibles avec une utilisation industrielle de ces membranes sont avantageusement employées. En particulier les supports tubulaires et les supports sous forme de fibres creuses permettent d'opérer des modules et des unités compactes (rapport surface de membrane/volume de l'équipement élevé) pour traiter des débits de charge importants.The support included in the zeolite / membrane support layer according to the invention is made of porous inorganic material. A ceramic support based on alumina and / or Zirconia and / or titanium oxide is a suitable support. Other materials, the nature of which follows, may also be suitable: carbon, silica, zeolites, clays, porous glass, porous metal. The use of an alumina support of alpha or gamma allotropic variety is preferred. This support may be, for example, in planar or tubular form or in the form of hollow fibers or many more multi-channel monoliths. Other geometries may be suitable, but the geometries of support compatible with industrial use of these membranes are advantageously employed. In particular tubular supports and supports in the form of hollow fibers allow to operate compact modules and units (membrane surface / volume ratio of high equipment) to handle large load flows.
La présente invention concerne également un procédé d'élaboration contrôlée des membranes zéolithiques selon l'invention.The present invention also relates to a process for the controlled production of membranes zeolites according to the invention.
Les membranes zéolithiques supportées selon l'invention sont avantageusement préparées par un
procédé qui comprend :
La source de silice employée dans l'étape (a) du procédé est de préférence une silice colloïdale ou une silice précipitée. Il peut également s'agir d'ions silicates tels que le silicate de sodium, d'alcoxydes de silicium ou du tétrachlorure de silicium.The source of silica used in step (a) of the process is preferably a colloidal silica or a precipitated silica. It can also be silicate ions such as sodium silicate, alkoxides of silicon or silicon tetrachloride.
D'autres éléments peuvent également être introduits en quantité minoritaire lors de l'étape (a) du procédé selon l'invention. En particulier, l'aluminium, le bore, le gallium, le titane, le germanium et le phosphore ainsi que le mélange de ces éléments peuvent être ajoutés lors de l'étape (a).Other elements can also be introduced in a minority quantity during step (a) of the process according to the invention. In particular, aluminum, boron, gallium, titanium, germanium and phosphorus as well as the mixture of these elements can be added during step (a).
Le composé organique polaire additionné au gel ou à la solution comprenant au moins ladite source de silice et l'eau est de préférence un composé basique. Il s'agit avantageusement d'hydroxydes organiques, tel que l'hydroxyde de tétrapropylammonium, d'agents structurants organiques contenant des paires ioniques (ions ammonium ou phosphonium et les anions correspondants) ou des molécules neutres (aminés, alcools ou éthers tels que les éthers-couronnes et les cryptands). Le rapport molaire du composé organique polaire à la silice est compris entre 0,3:1 et 0,6:1 et de préférence entre 0,35:1 et 0,50:1. Les ions hydroxydes ou fluorures peuvent par ailleurs être utilisés pour la dissolution des précurseurs et sont introduits dans le milieu de préparation par exemple sous forme d'hydroxyde de sodium, d'hydroxydes organiques et d'acide fluorhydrique.The polar organic compound added to the gel or to the solution comprising at least said source of silica and water is preferably a basic compound. Advantageously, these are hydroxides organic, such as tetrapropylammonium hydroxide, organic structuring agents containing ion pairs (ammonium or phosphonium ions and the corresponding anions) or molecules neutral (amines, alcohols or ethers such as crown ethers and cryptands). The molar ratio of the polar organic silica compound is between 0.3: 1 and 0.6: 1 and preferably between 0.35: 1 and 0.50: 1. Hydroxide or fluoride ions can also be used for the dissolution of precursors and are introduced into the preparation medium, for example in the form of hydroxide sodium, organic hydroxides and hydrofluoric acid.
La dilution de la source de silice dans la solution ou le gel utilisé dans l'étape (a) et la durée de cristallisation de la zéolithe dans l'étape (c) sont des paramètres essentiels à maítriser pour atteindre les propriétés désirées de la phase zéolithique déposée dans la porosité du support.The dilution of the silica source in the solution or gel used in step (a) and the duration of crystallization of the zeolite in step (c) are essential parameters to master in order to reach the desired properties of the zeolitic phase deposited in the porosity of the support.
Un mode de réalisation particulier du procédé selon l'invention consiste à utiliser une silice précipitée comme source de silice dans l'étape (a), dans un rapport molaire de l'eau à la silice compris entre 45:1 et 65:1 et à appliquer dans l'étape (c) une durée de cristallisation inférieure ou égale à 80 heures.A particular embodiment of the process according to the invention consists in using a precipitated silica as a source of silica in step (a), in a molar ratio of water to silica of between 45: 1 and 65: 1 and to apply in step (c) a crystallization time of less than or equal to 80 hours.
Un autre mode de réalisation particulier du procédé selon l'invention consiste à utiliser une silice colloïdale comme source de silice dans l'étape (a), dans un rapport molaire de l'eau à la silice compris entre 18:1 et 35:1 et à appliquer dans l'étape (c) une durée de cristallisation inférieure ou égale à 45 heures.Another particular embodiment of the method according to the invention consists in using a silica colloidal as source of silica in step (a), in a molar ratio of water to silica included between 18: 1 and 35: 1 and to apply in step (c) a crystallization time less than or equal to 45 hours.
Conformément à l'invention, la cristallisation de la zéolithe dans l'étape (c) du procédé selon l'invention est réalisée en une seule étape, c'est-à-dire que la zéolithe est cristallisée par un unique traitement hydrothermal.In accordance with the invention, the crystallization of the zeolite in step (c) of the process according to the invention is carried out in a single step, that is to say that the zeolite is crystallized by a single hydrothermal treatment.
L'élimination des agents résiduels, principalement du composé organique polaire, conformément à l'étape (d) du procédé selon l'invention, est effectuée par traitement thermique réalisé entre 350 et 550°C, de préférence entre 400°C et 500°C, dans un four sous atmosphère d'air ou sous atmosphère N2/O2 dans des proportions variables. Après élimination de ces agents résiduels, la microporosité des membranes zéolithiques peut alors être mise en oeuvre pour une opération de séparation. La calcination à haute température, c'est-à-dire réalisée entre 350 et 550°C, de préférence entre 400°C et 500°C, de la membrane afin d'éliminer les agents résiduels n'a aucune influence sur les performances séparatrices de la membrane, lesquelles demeurent très satisfaisantes. Cette très bonne résistance thermique de la membrane est avantageusement exploitée pour réaliser des séparations à hautes températures, dans des domaines où les membranes organiques ne peuvent être opérées du fait de leur faible résistance thermique. Les membranes zéolithiques selon l'invention apparaissent donc particulièrement adaptées pour des séparations à hautes comme à basses températures, dans des procédés industriels qui nécessitent de traiter des quantités de charge parfois importantes, tout en limitant l'investissement requis (membranes de hautes perméabilités).The removal of residual agents, mainly of the polar organic compound, in accordance with step (d) of the process according to the invention, is carried out by heat treatment carried out between 350 and 550 ° C, preferably between 400 ° C and 500 °. C, in an oven under air atmosphere or under N 2 / O 2 atmosphere in variable proportions. After removal of these residual agents, the microporosity of the zeolitic membranes can then be used for a separation operation. The calcination at high temperature, that is to say carried out between 350 and 550 ° C., preferably between 400 ° C. and 500 ° C., of the membrane in order to remove the residual agents has no influence on the performances. separators of the membrane, which remain very satisfactory. This very good thermal resistance of the membrane is advantageously exploited to carry out separations at high temperatures, in areas where the organic membranes cannot be operated because of their low thermal resistance. The zeolitic membranes according to the invention therefore appear to be particularly suitable for separations at high as well as at low temperatures, in industrial processes which require the treatment of sometimes large amounts of filler, while limiting the investment required (membranes of high permeability).
Aussi, les membranes zéolithiques selon l'invention peuvent être utilisées pour différentes séparations moléculaires. Elles sont avantageusement utilisées dans des procédés de séparation de gaz, de séparation de vapeurs ou de séparation de liquides. Ainsi, elles sont préférentiellement utilisées pour séparer :
- des paraffines linéaires et branchées (n- et iso-paraffines), comme par exemple le n-butane et l'isobutane,
- des paraffines branchées entre elles (mono-branchées et di-branchées ou multi-branchées),
- des oléfines linéaires et branchées (n- et iso-oléfines),
- des paraffines et des oléfines,
- des naphtènes et des paraffines,
- des paraffines et des aromatiques,
- de l'hydrogène et des hydrocarbures ; par exemple, dans les mélanges contenant l'hydrogène et les hydrocarbures suivants, présents séparément ou simultanément, les paraffines légères comme le méthane, l'éthane, le propane ou le butane et l'isobutane ; ou encore l'hydrogène et les oléfines légères comme l'éthylène, le propylène et les isomères des butènes, l'isobutène ; ou bien encore l'hydrogène et les hydrocarbures polyinsaturés comme l'acétylène, le propyne, butyne et butadiène, ces hydrocarbures étant pris séparément avec l'hydrogène ou en mélange,
- les isomères du xylène (ortho-, méta-, para-xylènes)
- le méthane et le CO2.
- linear and branched paraffins (n- and iso-paraffins), such as for example n-butane and isobutane,
- paraffins connected together (mono-connected and di-connected or multi-connected),
- linear and branched olefins (n- and iso-olefins),
- paraffins and olefins,
- naphthenes and paraffins,
- paraffins and aromatics,
- hydrogen and hydrocarbons; for example, in mixtures containing hydrogen and the following hydrocarbons, present separately or simultaneously, light paraffins such as methane, ethane, propane or butane and isobutane; or hydrogen and light olefins such as ethylene, propylene and the isomers of butenes, isobutene; or else hydrogen and polyunsaturated hydrocarbons such as acetylene, propyne, butyne and butadiene, these hydrocarbons being taken separately with hydrogen or as a mixture,
- xylene isomers (ortho-, meta-, para-xylenes)
- methane and CO 2 .
Conformément à l'invention, la qualité et les propriétés de tamisage moléculaire de la phase zéolithique sont mises à profit pour séparer des molécules dont les dimensions sont inférieures strictement d'une part et d'autre part supérieures strictement à celles des pores de la zéolithe (séparation par différentiation de taille). A titre illustratif, dans le cas de la zéolithe MFI qui présente une taille moyenne de pores de 0,55 nm (dimensions de canaux de 0.51*0.55 et 0.53*0.56 nm2), les membranes zéolithiques selon l'invention peuvent être utilisées pour la séparation de molécules, en particulier contenant des atomes de carbone et d'hydrogène, dont les dimensions sont d'une part inférieures à 0,45 nm environ et d'autre part supérieures à 0,55 nm. Par ailleurs, les interactions entre les molécules à séparer et la phase zéolithique de la membrane peuvent également être mises à profit pour réaliser la séparation desdites molécules (séparation par adsorption). In accordance with the invention, the quality and the molecular sieving properties of the zeolitic phase are used to separate molecules whose dimensions are strictly less on the one hand and on the other hand strictly greater than those of the pores of the zeolite (separation by size differentiation). By way of illustration, in the case of the MFI zeolite which has an average pore size of 0.55 nm (channel dimensions of 0.51 * 0.55 and 0.53 * 0.56 nm 2 ), the zeolitic membranes according to the invention can be used for the separation of molecules, in particular containing carbon and hydrogen atoms, the dimensions of which are on the one hand less than approximately 0.45 nm and on the other hand greater than 0.55 nm. Furthermore, the interactions between the molecules to be separated and the zeolitic phase of the membrane can also be used to effect the separation of said molecules (separation by adsorption).
Les exemples suivants illustrent l'invention et ne doivent en aucune manière être considérés comme limitatifs.The following examples illustrate the invention and should not in any way be taken as limiting.
On prépare une solution précurseur de zéolithe, à partir d'une source de silice (Aérosil 380® de surface spécifique égale à 380 m2/g commercialisé par la société Degussa), mélangée à température ambiante à de l'eau distillée et une solution aqueuse molaire de l'agent organique polaire d'hydroxyde d'ammonium tétrapropylé TPAOH (Fluka). La solution résultante admet pour composition molaire : 1 SiO2: 0,4 TPAOH : 63,7 H2O. Cette solution est laissée mûrir sous vive agitation durant 72 heures, ce qui permet une dépolymérisation partielle et une réorganisation de la silice en espèces silicates plus réactives que la source d'origine. Une gélification partielle des précurseurs peut intervenir, la solution étant plus ou moins limpide. Un support poreux d'alumine alpha (commercialisée par la société Exekia), préalablement lavé à l'eau distillée puis séché à 60°C, est ensuite immergé dans la solution préparée précédemment. L'ensemble des précurseurs et le support poreux sont placés dans un autoclave étanche, inséré dans une étuve maintenue à 175°C durant 60 heures. Après retour à température ambiante, la membrane est recueillie et lavée à l'eau distillée puis séchée à 60°C. L'élimination des agents résiduels, principalement l'hydroxyde d'ammonium tétrapropylé TPAOH, est effectuée par traitement thermique à 480°C dans un four sous atmosphère d'air. Après élimination de ces agents résiduels, la microporosité des membranes zéolithiques peut alors être mise en oeuvre pour une opération de séparation. L'analyse de phase par diffraction des rayons X sur cette membrane obtenue après 60 heures de séjour en autoclave confirme la présence de cristaux de zéolithe MFI localisés dans la porosité du support d'alumine alpha.A zeolite precursor solution is prepared from a source of silica (Aerosil 380® with a specific surface area equal to 380 m 2 / g sold by the company Degussa), mixed at room temperature with distilled water and a solution molar aqueous of the polar organic agent of tetrapropylated ammonium hydroxide TPAOH (Fluka). The resulting solution admits for molar composition: 1 SiO 2 : 0.4 TPAOH: 63.7 H 2 O. This solution is left to mature with vigorous stirring for 72 hours, which allows a partial depolymerization and a reorganization of the silica into species more reactive silicates than the original source. Partial gelation of the precursors may occur, the solution being more or less clear. A porous support of alpha alumina (sold by the company Exekia), previously washed with distilled water and then dried at 60 ° C., is then immersed in the solution prepared above. All the precursors and the porous support are placed in a sealed autoclave, inserted in an oven maintained at 175 ° C for 60 hours. After returning to room temperature, the membrane is collected and washed with distilled water and then dried at 60 ° C. Removal of residual agents, mainly tetrapropylated ammonium hydroxide TPAOH, is carried out by heat treatment at 480 ° C in an oven under air atmosphere. After removal of these residual agents, the microporosity of the zeolitic membranes can then be used for a separation operation. Phase analysis by X-ray diffraction on this membrane obtained after 60 hours of autoclaving confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
Le protocole de préparation est analogue à celui décrit dans l'exemple 1 mais la préparation est menée en présence d'une source de silice colloïdale, le Bindzil 40/130® (commercialisée par la société Akzo Nobel). On procède ainsi à la préparation d'une membrane zéolithique pour laquelle la solution précurseur de la zéolithe MFI, admet respectivement pour stoechiométrie molaire 1 SiO2 : 0,4 TPAOH : 18,3 H2O. La durée de cristallisation est de 30 heures. L'élimination des agents résiduels, principalement l'hydroxyde d'ammonium tétrapropylé TPAOH, est effectuée par traitement thermique à 480°C dans un four sous atmosphère d'air. Après élimination de ces agents résiduels, la microporosité des membranes zéolithiques peut alors être mise en oeuvre pour une opération de séparation. L'analyse de phase par diffraction des rayons X sur cette membrane obtenue après 30 heures de séjour en autoclave confirme la présence de cristaux de zéolithe MFI localisés dans la porosité du support d'alumine alpha.The preparation protocol is similar to that described in Example 1 but the preparation is carried out in the presence of a source of colloidal silica, Bindzil 40 / 130® (sold by the company Akzo Nobel). We thus proceed to the preparation of a zeolitic membrane for which the precursor solution of the MFI zeolite admits respectively for molar stoichiometry 1 SiO 2 : 0.4 TPAOH: 18.3 H 2 O. The crystallization time is 30 hours . Removal of residual agents, mainly tetrapropylated ammonium hydroxide TPAOH, is carried out by heat treatment at 480 ° C in an oven under air atmosphere. After removal of these residual agents, the microporosity of the zeolitic membranes can then be used for a separation operation. Phase analysis by X-ray diffraction on this membrane obtained after 30 hours of autoclaving confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
Le protocole opératoire décrit dans l'exemple 1 est repris en modifiant uniquement la quantité d'eau introduite dans la solution précurseur de la zéolithe MFI et la durée de cristallisation. La source de silice est l'Aérosil 380®. La durée de cristallisation est de 72 heures et l'élimination de l'hydroxyde d'ammonium tétrapropylé TPAOH est effectuée à 480°C.The operating protocol described in Example 1 is repeated by modifying only the quantity of water introduced into the precursor solution of the MFI zeolite and the crystallization time. The source of silica is Aerosil 380®. The crystallization time is 72 hours and the elimination of the hydroxide TPAOH tetrapropylated ammonium hydroxide is carried out at 480 ° C.
On procède ainsi à la préparation d'une membrane zéolithique pour laquelle la solution précurseur de la zéolithe MFI, admet respectivement pour stoechiométrie molaire 1 SiO2: 0,4 TPAOH : 29,6 H2O. L'analyse de phase par diffraction des rayons X sur cette membrane obtenue après 72 heure de séjour en autoclave confirme la présence de cristaux de zéolithe MFI localisés dans la porosité du support d'alumine alpha.One thus proceeds to the preparation of a zeolitic membrane for which the precursor solution of the MFI zeolite admits respectively for molar stoichiometry 1 SiO 2 : 0.4 TPAOH: 29.6 H 2 O. Phase analysis by diffraction of the X-rays on this membrane obtained after 72 hours of autoclaving confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
Le protocole opératoire décrit dans l'exemple 2 est repris en modifiant uniquement la durée de cristallisation. La source de silice est le Bindzil 40/130®. La durée de cristallisation est de 72 heures et l'élimination de l'hydroxyde d'ammonium tétrapropylé TPAOH est effectuée à 480°C.The operating protocol described in Example 2 is repeated by modifying only the duration of crystallization. The source of silica is Bindzil 40 / 130®. The crystallization time is 72 hours and the elimination of the tetrapropylated ammonium hydroxide TPAOH is carried out at 480 ° C.
On procède ainsi à la préparation d'une membrane zéolithique pour laquelle la solution, précurseur de la zéolithe MFI, admet respectivement pour stoechiométrie molaire i SiO2: 0,4 TPAOH : 18,3 H2O. L'analyse de phase par diffraction des rayons X sur cette membrane obtenue après 72 heure de séjour en autoclave confirme la présence de cristaux de zéolithe MFI localisés dans la porosité du support d'alumine alpha.One thus proceeds to the preparation of a zeolitic membrane for which the solution, precursor of the MFI zeolite, admits respectively for molar stoichiometry i SiO 2 : 0.4 TPAOH: 18.3 H 2 O. Phase analysis by diffraction X-rays on this membrane obtained after 72 hours of stay in an autoclave confirms the presence of MFI zeolite crystals located in the porosity of the alpha alumina support.
Cinq membranes (A, B, C, D, E) sont préparées selon le mode de synthèse décrit dans l'exemple 1. La membrane E est obtenue selon le mode de synthèse décrit dans l'exemple 1 mais avec une durée de cristallisation de 72 heures.Five membranes (A, B, C, D, E) are prepared according to the method of synthesis described in Example 1. The membrane E is obtained according to the method of synthesis described in example 1 but with a duration of 72 hour crystallization.
On teste également les performances d'une membrane F préparée selon le mode de synthèse décrit dans l'exemple 2.The performance of a membrane F prepared according to the described synthesis method is also tested. in example 2.
Les performances des membranes A, B, C, D, E et F selon l'invention sont mises en évidence par mesure de séparation de gaz (perméation gazeuse), réalisée en utilisant le n-butane et l'isobutane selon le protocole décrit plus haut dans la description. The performance of membranes A, B, C, D, E and F according to the invention are demonstrated by gas separation measurement (gas permeation), carried out using n-butane and isobutane according to the protocol described above in the description.
Les résultats sont rassemblés dans le tableau 1.
Les membranes zéolithiques selon l'invention présentent, à l'issue des mesures de caractérisation, des perméances très élevées, la plupart supérieures à 10.10-7mol/m2.s.Pa de n-butane à la température de 180°C, ce qui traduit une épaisseur très faible des membranes zéolithiques A, B, C, D, E et F. Dans les mêmes conditions, ces matériaux sont imperméables à l'isobutane (A, D, E, F) ou leurs perméances sont très faibles (B et C), dans tous les cas inférieures à 0,065.10-7 mol/m2.s.Pa d'isobutane. Par suite, la sélectivité n-butane / isobutane ou nC4H10/iC4H10 atteint des valeurs particulièrement élevées, dans tous les cas supérieures à 250 et la séparation est particulièrement efficace, ce qui témoigne de la continuité de la couche composite zéolithe / support de chacune des membranes selon l'invention. Cette couche est sélective pour séparer des isomères d'hydrocarbures dont les dimensions ne diffèrent que de 0,6 nanomètre (diamètre cinétique de 0,43 nm pour le n-butane et de 0,49 nm pour l'isobutane). Par comparaison, il est généralement admis dans la littérature que des membranes zéolithiques de type structural MFI présentent une bonne intégrité texturale, c'est-à-dire une absence de défauts de structure de type mésopore et macropore, lorsque la sélectivité n-butane/isobutane est supérieure à 10 (Vroon et al., J. Membr. Sci. 113 (1996) 293).The zeolitic membranes according to the invention exhibit, at the end of the characterization measurements, very high permeances, most of them greater than 10.10 -7 mol / m 2 .s.Pa of n-butane at the temperature of 180 ° C., which reflects a very small thickness of the zeolitic membranes A, B, C, D, E and F. Under the same conditions, these materials are impermeable to isobutane (A, D, E, F) or their permeances are very low (B and C), in all cases less than 0.065.10 -7 mol / m 2 .s.Pa of isobutane. As a result, the selectivity n-butane / isobutane or nC 4 H 10 / iC 4 H 10 reaches particularly high values, in all cases greater than 250 and the separation is particularly effective, which testifies to the continuity of the composite layer. zeolite / support for each of the membranes according to the invention. This layer is selective for separating isomers of hydrocarbons whose dimensions differ only by 0.6 nanometers (kinetic diameter of 0.43 nm for n-butane and 0.49 nm for isobutane). By comparison, it is generally accepted in the literature that zeolitic membranes of the MFI structural type exhibit good textural integrity, that is to say an absence of structural defects of the mesopore and macropore type, when the selectivity n-butane / isobutane is greater than 10 (Vroon et al., J. Membr. Sci. 113 (1996) 293).
La membrane préparée selon l'exemple 3a (membrane G) et celle préparée selon l'exemple 3b
(membrane H) sont soumises au même test de performances (perméation gazeuse) que les membranes
selon l'invention préparées selon les exemples 1 et 2. Les conditions de réalisation de la perméation
gazeuse avec le n-C4 et iC4 sont analogues à celles explicitées plus haut dans la description.
Les résultats sont rassemblés dans le tableau 2.
The results are collated in Table 2.
Les membranes G et H présentent dans la séparation n-C4/i-C4 des perméances de n-butane bien inférieures à celles des membranes selon l'invention. Les membranes selon l'invention présentent en effet une perméance de n-butane environ 2 à 11 fois plus élevée que celle des membranes non conformes à l'invention, tout en conservant des sélectivités élevées voire infinie. En d'autres termes, les membranes selon l'invention contiennent une couche composite zéolithe/support pouvant être jusqu'à au moins 11 fois plus fine que celle des membranes non conformes.The membranes G and H present in the n-C4 / i-C4 separation permeances of n-butane well lower than those of the membranes according to the invention. The membranes according to the invention have in effect a permeance of n-butane about 2 to 11 times higher than that of non-membranes in accordance with the invention, while retaining high or even infinite selectivities. In other words, the membranes according to the invention contain a zeolite / support composite layer which can be up to at least 11 times thinner than that of non-conforming membranes.
Claims (19)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR0206817 | 2002-06-03 | ||
| FR0206817A FR2840236B1 (en) | 2002-06-03 | 2002-06-03 | ZEOLITHIC MEMBRANE OF LOW THICKNESS, ITS PREPARATION AND USE IN SEPARATION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1369166A1 true EP1369166A1 (en) | 2003-12-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP03291117A Withdrawn EP1369166A1 (en) | 2002-06-03 | 2003-05-14 | Zeolith membrane of small thickness, its preparation and its use in separation |
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| Country | Link |
|---|---|
| EP (1) | EP1369166A1 (en) |
| JP (1) | JP2004026643A (en) |
| FR (1) | FR2840236B1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2894844A1 (en) * | 2005-12-21 | 2007-06-22 | Inst Francais Du Petrole | SUPPORTED ZEOLITHIC MEMBRANES, PROCESS FOR THEIR MANUFACTURE AND THEIR APPLICATIONS |
| US7829113B2 (en) | 2005-03-10 | 2010-11-09 | Mebiopharm Co., Ltd. | Liposome compositions |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2840296B1 (en) * | 2002-06-03 | 2004-08-20 | Inst Francais Du Petrole | PROCESS FOR THE PREPARATION OF A LOW THICKNESS ZEOLITHIC MEMBRANE |
| FR2871168B1 (en) * | 2004-06-04 | 2006-08-04 | Inst Francais Du Petrole | METHOD FOR IMPROVING ESSENTIAL CUPS AND GAS PROCESSING WITH COMPLEMENTARY TREATMENT FOR INCREASING THE YIELD OF THE GAS CUTTING |
| US8540800B2 (en) * | 2011-03-21 | 2013-09-24 | Uop Llc | Microporous UZM-5 inorganic zeolite membranes for gas, vapor, and liquid separations |
| JP6455923B2 (en) * | 2014-11-25 | 2019-01-23 | 学校法人早稲田大学 | Method for producing para-xylene |
| WO2016098417A1 (en) * | 2014-12-19 | 2016-06-23 | 学校法人早稲田大学 | Method for separating straight-chain conjugated diene |
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|---|---|---|---|---|
| EP0808655A1 (en) * | 1993-04-23 | 1997-11-26 | Exxon Chemical Patents Inc. | Molecular sieve layers and processes for their manufacture |
| WO2000053297A1 (en) * | 1999-03-11 | 2000-09-14 | Exxonmobil Chemical Patents Inc. | Crystalline molecular sieve layers and processes for their manufacture |
| US6140263A (en) * | 1995-12-08 | 2000-10-31 | Institute Francais Du Petrole | Process for the production of supported zeolite membranes, and zeolite membranes so produced |
| US6197427B1 (en) * | 1995-12-08 | 2001-03-06 | Institut Francais Du Petrole | Process for the production of zeolite membranes supported on porous glass and a zeolite membrane so produced |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996001687A1 (en) * | 1994-07-08 | 1996-01-25 | Exxon Research & Engineering Company | Zeolite layers with controlled crystal width and preferred orientation grown on a growth enhancing layer |
| JP2002058973A (en) * | 2000-08-18 | 2002-02-26 | Unitika Ltd | Method of manufacturing zsm-5 membrane using microwave |
| FR2840296B1 (en) * | 2002-06-03 | 2004-08-20 | Inst Francais Du Petrole | PROCESS FOR THE PREPARATION OF A LOW THICKNESS ZEOLITHIC MEMBRANE |
-
2002
- 2002-06-03 FR FR0206817A patent/FR2840236B1/en not_active Expired - Fee Related
-
2003
- 2003-05-14 EP EP03291117A patent/EP1369166A1/en not_active Withdrawn
- 2003-06-03 JP JP2003158150A patent/JP2004026643A/en not_active Ceased
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0808655A1 (en) * | 1993-04-23 | 1997-11-26 | Exxon Chemical Patents Inc. | Molecular sieve layers and processes for their manufacture |
| US6140263A (en) * | 1995-12-08 | 2000-10-31 | Institute Francais Du Petrole | Process for the production of supported zeolite membranes, and zeolite membranes so produced |
| US6197427B1 (en) * | 1995-12-08 | 2001-03-06 | Institut Francais Du Petrole | Process for the production of zeolite membranes supported on porous glass and a zeolite membrane so produced |
| WO2000053297A1 (en) * | 1999-03-11 | 2000-09-14 | Exxonmobil Chemical Patents Inc. | Crystalline molecular sieve layers and processes for their manufacture |
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| K.KUSAKABE ET AL: "morphology and gas permeance of ZSM-5-type zeolite membrane formed on a porous alpha-alumina support tube", JOURNAL OF MEMBRANE SCIENCE, vol. 116, 1996, Amsterdam,NL, pages 39-46, XP004041537 * |
| Z.A.E.P.VROON ET AL: "transport properties of alkanes through ceramic thin zeolite MFI membranes", JOURNAL OF MEMBRANE SCIENCE, vol. 113, 1996, Amsterdam,NL, pages 293-300, XP004041576 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7829113B2 (en) | 2005-03-10 | 2010-11-09 | Mebiopharm Co., Ltd. | Liposome compositions |
| US8758810B2 (en) | 2005-03-10 | 2014-06-24 | Mebiopharm Co., Ltd. | Liposome compositions |
| FR2894844A1 (en) * | 2005-12-21 | 2007-06-22 | Inst Francais Du Petrole | SUPPORTED ZEOLITHIC MEMBRANES, PROCESS FOR THEIR MANUFACTURE AND THEIR APPLICATIONS |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2840236A1 (en) | 2003-12-05 |
| FR2840236B1 (en) | 2005-02-04 |
| JP2004026643A (en) | 2004-01-29 |
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